Video posted in social media showed several 49ers and Cardinals fans exchanging shoves and then punches.

"It's very important if somebody has evidence like that, especially in instances like this, where we have conflicting witness statements, conflicting victim, suspect statements. It's very important that's brought to law enforcement attention," said Sgt. O'Neill.

A pile of people then tumbled a few feet down concrete stairs, leaving one man with a cut to his head.

O'Neill said 31-year-old Philip Martinez of Calimesa, California, was arrested for assault along with 37-year-old Daniel Mayerhofer of Surprise, Arizona.

One person identified as a victim was contacted by police while leaving the stadium but declined to press charges, O'Neill said.

He said several people were ejected following the fight around halftime of the game, which Arizona won 23-14.

By the end of the game, O'Neill said six people had been arrested and 39 others ejected from the stadium.

Arizona Cardinal player Darnell Dockett sent a tweet to show support for one of the people in the brawl.

He offered game tickets to the man wearing Dockett jersey who helped by punching a person who was choking a security guard.

"Who was the guy in the Dockett jersey in the brawl at the Cardinals game? Contact me I have some tickets for you," Dockett tweeted.

WARNING: The YouTube video contains language that some may find offensive.